Explanation

• Stars produce energy mainly through nuclear fusion in their cores.
• Hydrogen nuclei combine to form helium and release energy.
• The Sun also generates its energy through nuclear fusion.

Last verified on 11-11-2026

Explanation

• Our Solar System is located in the Orion Arm of the Milky Way galaxy.
• It including the Sun and eight planets.
• It consists of about 100–400 billion stars along with large amounts of gas and cosmic dust.

Additional information:

• The Milky Way is a spiral galaxy with a diameter of about 100,000 light-years.
• The nearest large galaxy to the Milky Way is Andromeda, located about 2.5 million light-years away.

Last verified on 11-03-2026

Explanation

• Mars is known as the Red Planet due to its reddish appearance.
• Its surface contains iron oxide (rust) which gives it a red color.
• It is the 4th planet from the Sun in the solar system.
• Mars has two small moons: Phobos and Deimos.
• Mars is often called the “planet of future exploration”.

Last verified on 11-11-2026

Explanation

• Length contraction is a prediction of Einstein's special theory of relativity.
• An object moving relative to an observer is measured shorter along its direction of motion.
• The effect becomes significant at speeds close to the speed of light.

Last verified on 11-11-2026

Explanation

• The photoelectric effect occurs when light of sufficient frequency strikes a material and ejects electrons.
• Einstein explained this phenomenon using the photon concept.
• It provided important evidence for the particle nature of light.

Last verified on 11-11-2026